Funds are requested to establish a diagnostic laboratory for research animals in the School of Medicine of the University of Pennsylvania. The laboratory will be a core element in the animal care program of the School of Medicine. Additionally, it will provide diagnostic services to other departments of the University and to biomedical institutions in Philadelphia. Diagnostic procedures performed by the laboratory will include necropsy, microscopic examination of animal tissues, isolation and identification of specific pathogens and other appropriate laboratory procedures. Emphasis will be placed on permanent documentation of laboratory findings for the benefit of investigators, professional and other graduate students. Specific programs which will be developed with the aid of the laboratory are: vendor surveillance; conditioning protocols; surveillance of resident animals; environmental surveillance; research assistance to investigators; diagnostic services and consultations to biomedical institutions; and in-depth investigations of unique conditions of laboratory animals. Long term objectives include provision of professional, scientific and academic services to investigators and students as an integral part of the multimillion dollar research activities which involve laboratory animals in the School of Medicine and in proximal institutions.